Many hearing loss patients have some degree of residual hearing in the low frequencies (e.g., below 1 kHz) and a severe hearing loss in the high frequencies (e.g., above 1 kHz). These people cannot benefit from traditional hearing aid amplification because of the severity of the hearing loss in the high frequencies. Nor are they classic cochlear implant candidates, because of their mostly intact low frequency residual hearing.
For this group of people, electro-acoustic stimulation (“EAS”) systems have been developed that provide such patients with the ability to perceive both low and high frequencies. Electro-acoustic stimulation combines the functionality of a hearing aid and a cochlear implant together in the same ear by providing acoustic stimulation representative of low frequency audio content and electrical stimulation representative of high frequency content. The auditory nerve combines the acoustic and electric stimuli into one auditory signal. Results of various studies have shown that electro-acoustic stimulation may enhance speech understanding, pitch discrimination, and music appreciation.
The effectiveness of an EAS system may be affected by a number of different factors. For example, surgical complications (e.g., a misalignment of an electrode array within the cochlea, destruction of hair cells during implantation of a cochlear implant, etc.) and post-surgery complications (e.g., residual hearing loss, wax buildup in the ear, infections, and component failure) may be detrimental to EAS system performance. Unfortunately, many of these factors are not readily discernible, thereby making it difficult or impossible to account for them (e.g., by adjusting one or more control parameters governing an operation of the EAS system). Hence, a patient may unknowingly suffer from sub-optimal EAS system performance.